Bucket



R. J. TAKACS Sept. 17, 1963 BUCKET 3 Sheets-Sheet l Filed June 22, 1960 I' ,/INVENTOR.

R. J. TAKACS sept. 17, 1963 BUCKET 3 Sheets-Sheet 2 Filed June 22, 1960 INVENTOR Raaf/fr Z' Kef/mcs BY m 2W/ W R. J. TAKACS Sept. 17, 1963 BUCKET 5 Sheets-Sheet 3 Filed June 22, 1960 OPE/V P06/770 N Pl United States Patent O 3,103,753 BUCKET Robert J. Takacs, Broadview Heights, Ohio, assigner to The Owen Bucket Company, Cleveland, liio, a corporation of Ohio Filed `lune 22, 1960, Ser. No. 37,76 21 Claims. (Cl. 37-187) This invention relates to improvements in a bucket and more particularly to an automatic grab bucket.

One of the objects of the present invention is to provide a bucket having positive power opening to fully open position, positive power closing to fully closed position and bowl locking in any intermediate position.

A further object of the presen-t invention is to provide a bucket having good digging characteristics and powered by a iluid operated piston and cylinder unit to move the bucket members between open and closed positions.

A further object or" the present invention is to provide a bucket having good digging characteristics 'by having during the `closing stroke `a larger closing force near the closed position than near the open Iposition.

A further object of the present invention is to provide a bucket having self-contained features wherein the bucket members are operated independenly of the support of the bucket.

A further object of the present invention is to provide a bucket characterized by its structural simplicity, strong and sturdy nature, operating efciency, economy of manufacture, ease of assembly of its component parts, and multiplicity of functional advantages for some corn-ponent parts.

Other features of 'this .invention reside in the arrangement and design of the parts for carrying out their appropriate functions.

Other objects and advantages of this invention will be apparent Jfrom the accompanying drawings and description and the essential features will be set forth in the ap-` pended claims.

In the drawings,

FIG. l is a side elevational view of the bucket disclosed herein lschematically shown on the end of a rigid boom;

FIG. 2 is a side elevational view of the bucket disclosed herein schematically shown with parts omitted and supported by a flexible line or cable;

FIG. 3 is a side elevationaly View of a first form of bucket disclosed herein with the bucket members shown in solid lines in closed position and shown in dot-dash lines in the fully opened position and in an intermediate position;

tFIG. 4 is a side elevational view of a second for-m of bucket, the same as the bucket in FIG. 3 except for the supporting construction thereof;

FIG. 5 is a side elevational view taken from the right of the bucket in FIG. 4; l

fFIG. 5A is a schematic ow diagram for the fluid motor and its control for opening and closing the bucket;

FIGS. 6 and 7 are force diagrams of the forces in the bucket occurring during the movement of the bucket members from open position to closed position with the diagram in FIG. 6 showing the forces near open position and the diagram in FIG. 7 showing the forces near closed position;

FIG. 8 is a graph of the forces exerted by the jaws of the bucket members during the closing operation with the forces of the present bucket generally shown in solid line and oi` some prior art buckets generally'shown in dotted line; while 1FIG. 9 is a graph of the downward force exerted by the net weight of the bucket during closing with the force exerted by the present bucket generally shown in solid Patented Sept. 17, 1963 ICC line and by prior art buckets with a closing cable generally shown in dotted lines.

Before the bucket here illustrated is specifically described, it is to be understood that the invention here involved is not limited to the structural details or arrangement of parts here shown since a bucket embodying the present invention may take various forms. It is also to be understood that the phraseology or terminology herein employed is for purposes of description and not of limitation since the .scope of the present invention is denoted by the appended claims.

While the present invention might be adapted to various types of load handling equipment, it has been chosen to show the same as applied to a grab bucket for illustration purposes.

vBucket lil includes head frame member l2, two bucket members li and i6, and power operated means 30 for power opening and closing of said bucket.

4Bucket members or bowls le. and lorhave respectively f position PZ (shown in solid line in FIG. 3) through an iny f termediate position P3 (also shown in dot-dash lines).

This connecting means includes spaced parallel lit-rst pivots connecting each of the bucket members to the head frame member, and link 18 pivotally connected by spaced parallel second pivots to said bucket members. These first pivots include, as one pivot, two coaxial pins 2i) pivotally connecting bucket member i4 to head frame member i2; and as another pivot, two coaxial pins 22 pivotally connecting bucket member lr6 to head frame member l2. `Link 13 is shown as two parallel link elements itin, la in FIG. 5, but it should be readily apparent that these may be replaced by a single, solid link. Head frame member l2 rigidly maintains these rst pivots Ztl and 22 in a constant spaced relationship by its rigidity; These tirs-t pivots 2t? and 22 are located outwardly from and straddling the second pivots, which comprise two coaxialiy aligned pins 2.4 at one end of link 18 and shaft 26 at the other end of link 18.

For Ibest operation, 'and especially to avoid any over bers 16. Non-symmetrical means that these distances ,are not `of equal length rand of the same angular orientation with respect to the vertical center line of the bucket '10.

When the bucket is in its fully opened position P1, this position Iis determined by engagement, in lateral alignment with each pin 2d in FIG. 5, of stopi surface 18b on link elements 18a against stop surface 28 rigidly v carried on bucket member i6. Engagement of these stop surfaces in position P1 in FIG. 3 prevents turning the bucket inside out during outward movement from position P2 toward position Pl, and establishes open position Pl.

Power operated means 3d -is adapted to `apply a force in the downward direction .to move bucket members 14l and .lo from closed position P2 to open position P1 andY to apply a closing force in the upward direction in FIG.

3 to move the bucket ymembers 14 and 16 from openV position P1 to closed position P2. f These forces :are exerted by a double acting iluid cylinder and piston unit 31 having telescopically connected cylinder 32, and the piston rod 36 therein. This unit 31 includes brackets on bucket member 14 and the lower end of cylinder 32 pivotally connected by shaft 33, and on the upper end of piston rod 36 pivotally `connected in FIG. 3 by shaft 38 to head frame member 12. These shafts 33 `and 33 provide the proper operative connection so that the endwise force applied by cylinder 32 and piston 36 is4 applied along a generally vertical line between pivots 20 land 22.

This double acting cylinder and piston unit 31 may be operated by any suitable uid, such as air or hydraulic liquid, and may be controlled in any suitable manner to move cylinder 32 in the downward direction to move bucket members from position P2 to position P1 or to move cylinder 32 in the upward direction so as to move bucket members from position P1 to position P2. This control may take the form in FIG. A of a conventional, manually controlled, four-way valve 41 having .two ports connected through a closed loop to fluid reservoir 42 and pump 43 arranged in series, and lhav-ing the other t-wo ports connected to ports at opposite ends lof cylinder 32. When valve 41 is in one position, the liuid is supplied under pressure by pump 43 through valve 41 to the lower end of cylinder 32 fand is exhausted from the upper end of cylinder 32 back through valve 41 to reservoir 42. Then, cylinder 32 moves downwardly and bucket members 14 and 16 will be moved from position P2 to position P1. Then, valve 41 may be moved to another position so as to reverse the flow into and out of cylinder 32. Then, cylinder 32 moves upwardly and :the bucket members will be moved back from position P1 to position P2.

Also, it should be apparent that link v18 operates in tension during movement of the bucket member from position P2 to position P1.

It should be readily apparent that iluid operated power unit 31 may be pivotally connected between head trarne member 12 and bucket member 16, instead of between members 12 and 14 as shown; `and then some of the desirable features of this bucket will still be obtained.

A bucket supporting means is secured to the bucket for supporting this bucket 10 rand to place it in position for working, that is for digging or discharging material. This means includes bracket 51 secured to the top of head frame member 12 in FIG. 3 or bracket 52 secured to bucket member 14, a cantilever type support member (such as boom 54 or endwise telescoping arm 55), and includes either holding line or cable 56 extending downwardly from said boom-like member in FIG. 2 or other connection in FIG. 1 at the end of arm 55. Two forms of the invention are shown in FIGS. 3 and 4 with the distinguishing structure on the bucket being `the use of bracket 51 or 52 thereon. Bracket 51 is pivotally secured to arm 55, or other suitable cantilever type sup-` port member, as shown in FIG. l, or is secured to cable 56, as schematically shown in FIG. 12. Then, cable 56 will have to be payed out, or arm 55 will have to be lowered, during the digging operation while the bucket members 14 and 16 move from open position P1 to 'closed position P2 to maintain lips 14a and '16a at the proper level to `obtain proper digging action. If cable 56 is attached to bracket 52 in FIG. 4, as schematically shown in FIG. 2, instead of being attached to bracket 51 shown in FIG. 3, bucket member jaws y14a and `16a will automatically remain at the proper digging level for digging, during bucket member movement toward closing position P2, without lowering said cable 56.

The disclosed apparatus, including bucket `1), has many desirable structural and operational characteristics set forth in detail in the following paragraphs.

First, power operated unit 31 in FIGS. 3 and 4, with its uid operated cylinder 32 and piston rod 36, provides positive and rapid power opening of bucket members 14 and 16 to fully open position P1, positive and rapid power closing to fully closed position P2, and locking in any intermediate position, such as position P3. rllhese bucket members will open quickly, and will close with great force, so as to provide maximum digging capacity for digging a maximum volume of material in minimum time.

Second, only one piston and cylinder unit 31 is required to move both bucket members 14 and 16 simultaneously both through the opening stroke from positions P2 to P1 and through the closing stroke from positions P1 to P2.

Third, bucket 10 has a simplicity of construction for minimum cost .of manufacture and maintenance whilc providing many desirable operational features, including more ecient and more rapid digging and dumping. Only link 18 is required to coordinate, and move simultaneously between the illustrated positions, the inner ends of the bucket members 14 and 16, rather than a complex mechanism including vertical guides, toggle links, a plurality of links, or gears, all of which mechanisms have high maintenance costs and are difficult to adjust and maintain. No locks are required to hold the bucket members in open position P1 after gravity has partially opened them.

Fourth, the bucket members are easily and quickly moved to open position P1 by power and are heldin position P1. Since closing cables are not required, minimum frictional resistance is encountered during the bucket opening operation by the downward force exerted by iiuid power unit 31. Since the bucket members are opened by power instead of by gravity, no lock mechanism is `required to hold them in the fully open position P1.

Fifth, a one-piece, rigid head trame member 112 is provided for simplicity of construction. Also, since the rigidity thereof maintains the pivots 20 and 22 thereon a iixed distance apart, good digging characteristics are obtained. Now, these pivots provide an unyielding reaction by which bucket member closing unit 31, exerting an upward force in a substantially vertical direction, exerts maximum force between jaws 14a and 16a as the bucket members approach closed position P2, as will be brought out more in `detail hereinafter.

Sixth, bucket 10 has better digging characteristics than a bucket with a closing line or cable because piston and cylinder unit 31 provides a self-contained bucket wherein the forces exerted by this unit (its upwardly directed closing force on shaft 33 and its reaction lforce on shaft 38) are exerted only on the members of bucket 10 with these including respectively members 14 and 12. This upwardly directed closing force on shaft 33` is applied independently of 'the supporting force applied to bucket 10 by cable 56 or -by member 54 or 55 of the bucket supporting means.

In a bucket having a closing cable, this closing cable is pulled upwardly to close the bucket so that this upward pull will exert a liting 'tendency on the bucket to reduce the net bucket weight, as shown for example by the net bucket weight curve A for hard digging material and curve B for easy digging material in FIG. 9. This may cause the bucket to prematurely lift from the ground, such as at point C, when it has grabbed a load of weight E so that either an under sized load is grabbed or the load in the unclosed jaws is dropped. In the present construction, no such closing cable is provided so that the bucket maintains a constant net weight along solid line D to exert the essential downward pressure against rthe material by jaws 14a, 16a and by teeth 14b, i16b, so

that a full size load will be grabbed by bucket 10. Since both the closing force and reaction force of unit 31 are contained within bucket 10, no such lifting tendency (corresponding rto upward pull of a closing cable) `on bucket 10 will be experienced.

Seventh, bucket 10 is constructed so that a given upwardly directed, jaw closing force exerted by cylinder and piston unit 31 causes bucket members 14 and 16 to exert a digging force between their jaws 14a and 16a near closed position P2 greater than near open position torque exerted on these lips 14a and 16a.

P1. This provides substantially better digging characteristics, by operation along curve G in FIG. 8, than some prior art bucket-s operating along curve H in FIG. 8. The jaws in applicants construction have a faster movement during the leftportilon or curve G during the beginning of the closing action (because they exert less torce) so that fast closing of the bucket is permitted, require less closing power (as shown by the smaller area under curve G than under curve H), and exert a greater closing force as they approach position P@ lat the right end of curve G so as to bite oli tougher material.

Applicants force relationships on the members of the bucket during the jaw closing position are shown by force diagrams in FIGS. 6 yand 7 With the `diagram in FIG. 6 being in the open position P1 and the diagram in FIG. 7 in the closed position PZ. force analysis is made in the usual manner tor determining forces on bucket components wherein the weight of the bucket is excluded; the forces are considered as extending through lips or jaws 14aI and 16a because the bucket members may be used without teeth 114]) and i16b; and a horizontal outward force is assumed to be exerted fon each tot these jaws duri-ng the closing operation. Now, consider FIGS. 4 and 7. Line J extends through fpivot shafts 313 andS, line N extends horizontally through jaws 14a and 16a, line M extends through link pivots 24 and 26, line L extends through pivot ZZ and the intersection or lines M and N, and line K extends through pivot 20* and the intersection lof lines J and L. Since the fluid in cylinder 32 will exert la substantially constant nforce throughout the closing stroke, this force is laid out as forces FJ in FIG. 7 along line I. Since the three forces acting lonrhead frame member y12 must intersect, the length lof :force FJ exerted on pin I3S by unit 31 determines force FL acting on pivot 22 and force `FK acting on pivot Z0. Line K is drawn parallel to line K to determine (forces FL and FK. Then, lines M' and -N are drawn parallel respectively to lines M and N to complete the force diagram in FlG. 7. Now, the forces are formed by these lines; and these forces FI, FK, FL, FM, and FNC are shown by heavy black lines in FIG. 7. Now, it should be evident that the :forces acting on left-hand bucket member or tray 14 are forces FJ at pivot 33, FNC at lip 14a, force FK at pivot 20, and force FM at pivot 26. The forces on the right-hand bucket member 16 include force FL at pivot 22 force FNC :at lip 16a, and force FM at pivot 24. The forces on 4lips 14a and 16a are equal and opposite' ofrces FNC acting in opposite directions with one force acting on each of these lips. lThe force diagram in FIG. 6 is made in substantially the sante Way -for open position P1. Forces Fl in both FIGS. 6 and 7 are of thesame length because the uid in cylinder '32 willexent a substantially constant force throughout the closing stroke. Hence, the forcesv on jaw-s 14a and 16a in their respective open and closed positions P1 and P2 are shown respectively by force FNO and FNC in FIGS. 6, 7 and 8, and -eachlof these jaw liorces generally move along curve G in FIG. 8 during the closing operation.

Now, .it should be apparent that applicant has a greater closing force FNC near closed position P2 than force FNO near open position Pd. This maybe expressed in another lway by considering the resisting moment or The resisting forces FNO or FNC on these lips act along horizontal lines N in FIGS. 4, 6 and 7 so that thefresisti-ng torque or moment is a product of this force and the (perpendicular distance therefrom to pivot yor `fulcrurn 20 -or 22. vIt should be noted that when lip 14a is directly below pivot or fulcrum 20 during jaw closing, this perpendicular `distance 4will decrease as the jaws move toward closed position P2 because the resistance plane N approaches these fulcrums 20 and 22. Therefore, for a given closing torque, the torce will increase, as shown by force FNC.

Applicants bucket 10, ope-rating along curve G in FIG. 8, has more desir-able operating characteristics than prior Sant buckets operating :along curve H. 'Fhese prior art buckets include :a pair of bowls pivotally connected together at their adjacent inner ends, pivo-tally mounted links at their outer ends, a head block pivotally supported by these links, and a bowl closing power unit pulling the head block toward the inner ends of the bowls to close the bucket. This prior art bucket has a high force in the jaw open position and a low closing force in the jaw closed position, as shown by curve H.

If this last mentioned bucket has a cable type closing line, the lower end of curve A in 'FIG. 9 will be displaced further toward the left because a greater pulling force must be exerted upwardly on the :closing line to exert the proper closing force, and thus the net weight of the bucketis reduced. Since the bowls are pivotally connected together at their adjacent inner ends near the vertical center line of the bucket, these connections actas a fulorurn. Hence, a torque or resisting moment analysis of this bucket may be made corresponding with this same type analysis earlier made `for bucket 10. In this prior art bucket, the jaws of the bowls, when moving toward each other 'toward closed position, are so arranged that the force exerted on the jaws by the material in the resistance plane of the material, corresponding Ito line N in FIGS. 6 yand 7, constantly moves downwardly away from these fnlcrurns so that the resisting moment will increase progressively so as to make necessary an increasing upward pull on the closing cable in order to maintain this Iclosing movement. Hence, this construction compounds the disadvantages of curves H and A in FIGS. 8 and 9 to'provide very poor digging characteristics.

Applicants bucket lll has-no such defects because it operates lalong curves G and D in FIGS. 8 and 9 respeca tively. 'Ihis bucket has a good operating factor, which is the [dominant factor governing digging performance Iand is the ratio between the horizontal lforce FNO ror.

FNC on cutting edges 14a and 16a and the internal closing power of the bucket exerted as force FJ. At the beginning of the closing stroke from position P1 to posi-V tion P2, the jaws in position P1 are disposed at a relatively great vertical angle With respect to line N in FIG. 6 and hence merely scrapes through the material without being able to penetrate or engage this material to any important degree. Therefore, only relatively slight relsistance is encountered and a low `closing force (shown herein as force FN'O) by these jaws is not only sufficient but desirable in order that the jaws will `close las quickly as possible. Conversely, as jaws 414a and 16a advance through the material idu-ringthe last half of the closing stroke to approach position P2, these jaws rare positioned at a relatively small vertical tangle with respect to plane N in FIG. 7 so that rm engagement with the bed of unloosened material yis obtained. Relatively great closing resistance is encountered because of this -rm engagement 1and the necessity for compressing the material `a1- ready loosened 'and scraped bowls 14 and 16. ,Now larger force FNC in FIG. 7,is required, and is provided by applicants bucket 10, in order to maintain closingY movement of these jaws. v

lNow it 4should be apparent that a bucket having a greater closing force during the'iirst portion of the stroke, as shown by curve H in FIG. 8, will not scrape together substantially more material than one having a relatively low closing force than tapplicants bucket operating on curve G, but that the formerV will require more time for the same movement. Also, a bucket, having -a high clos- 'ing force during the last portion of the stroke (see curve G) as -applicants bucket 10, will have deeper penetration and secure more material between the bowls ,14 and 16 than one having a smaller closing force (see curve H);

Therefore, applicants bucket 10, operating on curves D Iand G, has substantially better operating characteristics than buckets operating on curves A, B or H.

'Various changes in details 'and arrangement of parts 7 can be made by one skilled in the art without departing from either the spirit of this invention or the scope of the appended claims.

What is claimed is:

1. A bucket, comprising a head frame member, two bucket members, connecting means operatively connecting said members together for relative movement of jaws on said bucket members between open position and closed position, power operated means for applying a force for moving said bucket members from one of said positions to another of said positions, and bucket supporting means secured to one of said members so that the jaws thereof will remain at the proper digging 'level during bucket member movement toward closing position without lowering said bucket supporting means.

2. A bucket comprising a head frame member, two bucket members, connecting means operatively connecting said members together for relative movement of jaws on said bucket members between open position and closed position, power operated means for applying a force for moving said bucket members from one of said positions to another of said positions, said connecting means including spaced first pivots connecting each of said bucket members to said head frame member, and including a link connected by spaced second pivots to said bucket members, said power operated means including means for applying an opening force and a closing force to move said bucket members to both open position and closed position respectively, said head frame member rigidly maintaining said first pivots in a constant spaced relationship, said first pivots being located outwardly from and straddling said second pivots, said power actuated means including means operatively connecting it to said head frame member and at least one of said bucket members for applying said force along a line between said first pivots, the distance between said iirst and second pivots on one of said bucket members being nonsymmetrical with the corresponding distance on the other of said bucket members.

3. A bucket comprising a head frame member, two bucket members, connecting means operatively connecting said members together for relative movement of jaws on said bucket members between open and closed positions, power operated means for applying a force for moving said bucket members from one to the other of said positions, said connecting means including spaced iirst pivots connecting each of said members to said head frame member, and including a =link connected by spaced second pivots to said bucket members, said power operated means including means for applying an opening force and a closing force to move said bucket members to both open position and closed position respectively, said head frame member rigidly maintaining said first pivots in a constant spaced relationship, said first pivots being located outwardly from and straddling said second pivots, said power actuated means including means operatively connecting it to said head frame member and to at least one of said bucket members for applying said force along a line between said first pivots, bucket-supporting means secured to one of said members for supporting said bucket so that the jaws of said bucket members will remain at the proper digging level during bucket member movement toward closing position without lowering said bucket supporting means.

4. A bucket comprising a head frame, two bucket members each pivotally mounted on said frame, connecting means operatively connecting said members together for relative movement of jaws on said bucket members between open position and closed position, power operated means supported on said frame and having a movable part in operative contact with one only of said bucket members for applying a force for moving said bucket members from one of said positions to the other of said positions.

5. A bucket as defined in claim 4 wherein said connecting means which operatively connects said members consists of a link pivoted at one end to one of said members and at the other end to the other of said members.

6. A bucket as defined in claim 4 wherein supporting means is provided for carrying said head frame, said supporting means being operatively independent of said power operated means.

7. A bucket as defined in claim 4 wherein said power operated means consists of double acting piston-cylinder members, one of the piston-cylinder members being connected Ito said frame and the other to the bucket member.

8. A bucket comprising a head frame, two bucket members, each pivotally mounted on said frame at rcspectively spaced points, link means operatively connecting said members together independent of said frame for relative movement of jaws on said bucket members between open position and closed position, power-operated means supported on said frame and having a movable part in operative contact with one only of said bucket members for applying a force for moving said bucket members from one of said positions to the other of said positions said movable part of said power operated means being extendable and retractable within a zone between said spaced pivots.

9. A bucket, comprising-a rigid head frame member, two bucket members independently pivotally connected to said head frame member by rigidly spaced apart pivots for relative movement of jaws on said bucket members between open position and closed position, and power means for closing said bucket and for opening said bucket by applying a force for moving said `bucket members between said positions, the connections between said members and power means including means operatively connecting said members and power means so that a given closing force by said power means causes said bucket members to exert a digging force between their jaws near closed position greater than near said open position.

10. A bucket, as set forth in claim 9, lwith said power means being constructed to open said bucket in any bucket oriented position.

l1. A bucket, as set forth in claim 9, with said power means comprising a double acting, uid pressure actuated cylinder and piston unit.

12. A bucket, comprising a head frame member, two bucket members, connecting means operatively connect- -ing said members together for relative movement of jaws on said bucket members between open position and closed position, and power operated means for appljn'ng a force for moving said bucket members from one of said positions to another of said positions, said connecting means including spaced first pivots connecting each of said bucket members to said head frame member, and including a. link connected by spaced second pivots to said bucket members, said power operated means including means for applying an opening force and a closing force to move said bucket members to both open position and closed position respectively, said head :frame member rigidly maintaining said first pivots in a constant spaced relationship, said first pivots being located outwardly from and straddling said second pivots, said power actuated means including means operatively connecting it to said head frame member and at least one of said bucket members for applying said force along a line between said first pivots, a bucket supporting means secured to one of said members for supporting said bucket, the distance between said first and second pivots on one of said bucket members being nonsymmetrical with the corresponding distance on the other of said bucket members; said power means including a double acting fiuid cylinder and piston unit forexerting said closing force; and means operatively connectingsaid members, connecting means, and power means so that a given force by said power means causes said bucket members to exert a digging force between their jaws near closed position greater than near said open position, so that said closing force is applied independently of the supporting force applied to said bucket by said bucket supporting means and so that the closing and reaction forces exerted by said unit are exerted only on said members to provide a self-contained bucket.

13. A bucket, comprising la head frame member, two bucket members, connecting means operatively connecting said members together for relative movement of jaws on said bucket members between open position and closed position, and power operated means for applying a force for moving said bucket members from one of said positions to another of said positions, said connecting means including spaced first pivots connecting each of said bucket members to said head frame member, and including a link connected by said second pivots one to each of said bucket members with said second pivots spaced apart in the plane of jaw opening and closing movement, said power operated means including means for applying an opening force and a closing force to move said bucket members to both open position and closed position respectively, said head frame member rigidly maintaining said firs-t pivots in a constant spaced relationship, said first pivots being located outwardly from and straddling said second pivots, said power actuated means including means operatively connecting it to said head frame member and at least one of said bucket members for applying said force lalong a line between said iirst pivots.

14. An apparatus, comprising a bucket, as set forth in claim l13, with a bucket supporting means secured to one of said members for supporting said bucket.

l5. An apparatus, 'as set forth in claim 14, with said bucket supporting means including a holding cable.

16. An apparatus, as set forth in claim 14, with said bucket supporting means including a cantilever type support member.

17a An apparatus, as set forth in claim i14, with said bucket supporting means being secured to the top of said head frame member.

18. A bucket, comprising a head frame member, two bucket members, a link connecting said members together for relative movement of jaws of said bucket members between lopen position and closed position, each bucket member having a lirst pivot on said head frame and a secondpivot on said link, the distance between said first and second pivots on one oct said bucket members being non-symmetrical with the corresponding distance on the other of said bucket members, and power operated means for applying a force for moving said bucket members from said closed position to said open position in fany orientation of said bucket.

19. A bucket, comprising a head frame member, two bucket members, connecting means operatively connecting said members together for relative movement of jaws on said bucket members between open position and closed position, and power operated means ior applying a force for moving said bucket members from one yof said positions to another of said positions, said connecting means including a link pivotally connected to each of said bucket members, said power means being connected to said head frame member and to one bucket member spaced from said link and the pivotal connections on said link.

20. A bucket, comprising la |head frame member, two bucket members, connecting means operatively connecting said members together for relative movement of jaws on said bucket members between open position and closed position, power operated means for applying a :force for moving said bucket members from one oi said positions to another of said positions, said power operated means including means for yapplying an opening force and a closing force to move said bucket members to both open position and closed position respectively; and means operatively connecting said members, connecting means, and power means so that a given closing force by said power means causes said bucket members to exert a digging force between their jaws near closed position greater than near said open position.

21. A bucket, comprising a rigid head frame member, two bucket members independently pivotally connected to said head frame member by rigidly spaced apart pivots for relative movement 'of jaws on said bucket members between open position and closed position, and power means for closing said bucket and for opening said bucket by applying a force for moving said bucket members between said positions so that a givenclosing force by said power means causes said bucket members to exert a digging force between their jaws near closed position greater than near said open position, a rigid link means movable relative to said head frame member and having two rigidly spaced apart pivots with each pivot connected to a diierent bucket member.

References Cited in the tile of this patent UNITED STATES PATENTS 2,377,184 Robin May 29, 1945 2,382,955 Billings Aug. 21, 1945 2,840,254 Bevan June 24. 1958 2,889,643 Cihatrenet June 6, 1959 FOREIGN PATENTS 145,620 Australia Mar. 6, j1952 1,136,122 France Dec. 22, 1956 795,579 Great Britain May 28, 1958 UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No, 3,103,753 September I7, 1963 Robert J. Takacs error appears in the above numbered pat- It is hereby certified that tters Patent should read as ent requiring correction and that the said Le corrected below.

Column 5, line 48, line 23, after "positions" insert a comme; column 9, line 5,

after "means" insert a comma; line 17, strike out "said".

Signed and sealed this '7th day of Apr-i1 1964a (SEAL) Attest: EDWARD T. BRENNER ERNEST W. SWIDER Attesting Officer Commissioner of Patents for "ofrces" read forces column 8, 

9. A BUCKET, COMPRISING A RIGID HEAD FRAME MEMBER, TWO BUCKET MEMBERS INDEPENDENTLY PIVOTALLY CONNECTED TO SAID HEAD FRAME MEMBER BY RIGIDLY SPACED APART PIVOTS FOR RELATIVE MOVEMENT OF JAWS ON SAID BUCKET MEMBERS BETWEEN OPEN POSITION AND CLOSED POSITION, AND POWER MEANS FOR CLOSING SAID BUCKET AND FOR OPENING SAID BUCKET BY APPLYING A FORCE FOR MOVING SAID BUCKET MEMBERS BETWEEN SAID POSITIONS, THE CONNECTIONS BETWEEN SAID MEMBERS AND POWER MEANS INCLUDING MEANS OPERATIVELY CONNECTING SAID MEMBERS AND POWER MEANS SO THAT A GIVEN CLOSING FORCE BY SAID POWER MEANS CAUSES SAID BUCKET MEMBERS TO EXERT A DIGGING FORCE BETWEEN THEIR JAWS NEAR CLOSED POSITION GREATER THAN NEAR SAID OPEN POSITION. 